The present invention relates to a method for producing and repairing a part comprising at least two metal components joined together, in particular, components of a gas turbine, the joining and connection of the corresponding joining surfaces of the components being conducted by means of a pressure welding process, and in the joining process, a machining allowance is upset in the region of a joining zone of the two joining surfaces. In addition, the invention relates to a part produced by the named method.
Slender three-dimensional geometries of metal parts, such as for example, Blisk rotor blades, are usually processed from a solid material. Of course, combinations of materials cannot be used here. These geometries, which are sparing of materials and versatile in application can be produced by means of a joining process. Different methods of the prior art are known for joining metal components by means of inductive high-frequency pressure welding. Thus, for example, DE 198 58 702 A1 describes a method for joining blade parts of a gas turbine, wherein a thin blade section and at least one other blade part are provided. Here, corresponding joining surfaces of these elements are positioned essentially flush at a distance from one another and subsequently are welded together by exciting an inductor with high-frequency current and bringing them together with contact of their heated joining surfaces. The inductor is excited with a constant frequency, which in general lies above 0.75 MHz. The frequency is also selected as a function of the geometry of the joining surfaces. Additional inductive high-frequency pressure welding methods are known from EP 1112141 B1 and EP 1140417 B1. In addition, it is known to join components by means of linear friction welding methods. In the case of thin-walled parts, such as, for example, thin-walled turbine blades, this method, however, is no longer applicable, since the existing geometry of distancing [the two parts]* impedes the introduction of the friction force. The joined part usually has a machining allowance, which must then be machined in order to obtain a desired final contour. Thus, whether it is the case of Blisk rotor blades, corresponding to the use of a blade that already has a final contour in the thin blade region, or it is the case of using of a blade that has machining allowances, in each case, the joining zone or the overall blade must be machined. In the case of rigid blades, for example, this can be achieved by an adaptive cutting process. In the case of thin part structures, however, due to the cutting forces that occur, this may lead to damage, especially to a bending of the structure, such as, for example, a blade geometry. *Note: Words or phrases enclosed in brackets are added by the translator.